adds new test for https basic auth login

what the test does now:
1 - loads browser
2 - goes to http://mozqa.com/data/mozqa.com/http_auth/
3 - fills the browser login form
4 - fails on trying to see if the user is logged in (it probably is not the
right way)

waits for success page to be loaded to verify success

adds test to manifest.ini

refactoring for authentication_dialog region

- moves login items such as username and password input to authentication
dialog region
- uses send_keys on inputs, instead of keyboard.send
- uses authenticate method from region
- tests if correct message is displayed on correct place using xpath

oops! parameters passed were not being used

Trying to find a pattern to write the test.

- Uses By instead of root_element to find elements on page.
- Uses more efficient and human-readable names for methods inside the
region.
- Writes the funcional test on an inline way instead of using methods.